Many conventional condensation reactions utilize inorganic acid catalysts, such as sulfuric acid or hydrochloric acid. Use of such inorganic acid catalysts can result in the formation of undesirable byproducts that must be separated from the reaction stream. Ion exchange resin catalyst systems can also be used, but the inherent low acid concentration can require the use of a promoter or rate accelerator.
When used as part of the catalyst system, reaction promoters can improve reaction rate and selectivity. In the case of the condensation of phenol and ketone to form bisphenol-A (BPA), reaction promoters can improve selectivity for the desired para-para BPA isomer.
Reaction promoters can be used as bulk promoters, where the promoter is present as an unattached molecule in the reaction medium, or as an attached promoter, where the promoter is attached to a sulphonic acidic portion of the catalyst system.
In the synthesis of BPA, the use of 3-mercaptopropionic acid (3-MPA) can produce a significant quantity of the less desirable o,p-BPA isomer, as opposed to the preferred p,p-BPA isomer.
While much effort has been applied to the development and use of bulk and attached promoter systems, a need still exists for a manufacturing process and promoter catalyst system that can provide high purity reaction products. Thus, there is a need to address these and other shortcomings associated with existing promoter catalyst systems. These needs and other needs are satisfied by the compositions and methods of the present disclosure.